Support Async HTTP

[Ugbot]

TL;DR : replace the requests lib with HTTPX and get Async requests and http/2 support.

Python from 3.4 onwards has added Async support for IO in the asyncio package. This is increasingly core to modern python development with tools like fastAPI and django.

The core http library "requests" has lagged behind and is missing support for this along with the HTTP/2 standard.

By replacing requests with HTTPX we can achieve both these goals via a configurable interface.

This would not support any version without asyncio but its reasonable trade-off for onwards performance improvements.

┆Issue is synchronized with this Jira Story by Unito

[Ugbot]

We are making breaking changes with the Async work, Can we clean up the publish method?

Currently it takes *args & *kwargs rather than ideally typed fields.

Can we make the publish function take less wildcard data and have a "legacy" publish method if needed.

[d8x]

@Ugbot Thank you for the proposal. This is good idea in general. But the pull-request is already quite big and introducing another API SDK changes would make it even bigger. Maybe we should do it in separated pull-request?